I have mentioned folding in passing in a previous post, but I thought I'd give you a proper look at one of the many processes involved in making a pair of shoes.
When designing a shoe, one of the aspects of the overall look to consider is the finish of the seams when one piece is stitched overlapping another. The two main options are raw edge and folded edge. A raw edge is produced by cutting out the pattern piece in leather and stitching it to another piece with the cut edge exposed. This is the faster, cheaper option. A folded edge is where the cut edge of a piece of leather is carefully folded over before being stitched to another piece. This method takes more time and is more fiddly but the outcome is a sleeker, more finished looking shoe.
A folded edge needs to be built into the shoe at the patterncutting stage. A folding allowance (like a seam allowance) is added to any edge that is to be folded, this is usually 5mm. This edge of the leather needs to be skived - the bulk from the underside of the edge is trimmed away allowing the edge to be folded easily without adding bulk to the seam.
Some people can do their folding by eye. I like this method as, although it takes a little longer, it ensures all curves are consistent and matching.
Here's how I do it...
You will need:
Pattern piece with folding allowance marked, leather piece with folding edge skived, sharp knife, awl (or other pointy tool) folding hammer, jumbo paper clips.
The underside of the leather is shown here, this is the side I will be working on.
Depending on the piece you are working on, you may also need topline tape. This will stop the leather from stretching out of shape during the life of the shoe.
I have added topline tape, as this section of the boot includes the facings - where the eyelets will go, as well as the topline of the boot. Topline tape should run along the edge of the leather piece approximately 5mm from the edge. I have also glued the folding area.
You may just be able to see that I have made tiny cuts along the concave curve. This will allow the leather to fold over more easily. Cuts should be no more than 2mm otherwise they will be seen on the finished folded curve.
I place the leather piece over its corresponding pattern piece, securing it with the jumbo paperclips, ensuring that the paperclips are not distorting or damaging the leather. You can see that the folding allowance has been marked on the pattern. This will be my guide.
I usually start with the convex curves. I need to compress the extra leather of the folding allowance into the smaller space of the finished curve, I do this by evenly distributing the extra leather and manipulating it into tiny pleats. Using the awl I fold over the leather at the apex of the curve until it matches the apex of the curve marked on the pattern piece. Next I fold the points at the beginning and end of the curve, again using the fold line on the pattern piece as a guide.
I then divide the two pleats on either side of the centre of the curve into two smaller pleats. Using the awl it is possible to push/pull/manipulate the leather to match the guide line.
I then divide these smaller pleats into even smaller ones, again making any fine adjustments to ensure a smooth curve.
For concave curves, we have the opposite situation, there is less leather in the folding allowance than is required for the curve. The tiny cuts I made in the edge of the folding allowance allows the leather to stretch just enough that the leather will fold without distorting.
Again I start in the centre of the curve, folding it back far enough to match the guide line on the pattern piece, I then work one side of the curve then the other away from the centre, stopping before the next curve begins.
At this point I would start working on the next convex curve at the top of the shot in the same way as before - dividing it into smaller and smaller even pleats. I then fold the remaining areas between the curves.
When it is all neatly folded, I use the folding hammer to delicately bash it all nice and flat.
And there you have a beautifully folded edge! Because I used the pattern piece as a guide, all corresponding pieces will have perfectly matching curves.